There are provided in the art some medicine packing devices, which pack medicines such as tablets or powdered medicines one dose at a time according to a prescription. As one example of such type of medicine packing device, a medicine packing device, which includes a tablet feeding unit feeding tablets in a so-called manual distributing manner, is known in the art (see, e.g., Patent Document 1). Specifically, such type of a tablet feeding unit includes a plurality of tablet receiving measures arranged in a matrix shape on an upper surface of a medicine packing device. An operator manually puts tablets into the tablet receiving measures. After putting the tablets is completed, a shutter constituting a bottom portion of the tablet receiving measure is opened. Then, the tablets in each of the tablet receiving measures drop into a corresponding tablet dispensing measure provided in a movable tablet dispensing member. The tablets in the tablet dispensing measure are sequentially fed to a packing unit by means of a below-described mechanism.
Referring to FIG. 17, a lower opening of each of the tablet dispensing measures 542 is provided with a bottom plate 543. A pin 544, which is supported at its both ends by the tablet dispensing measure, penetrates through a base end of the bottom plate 543. The bottom plate 543 is rotatably connected to the tablet dispensing member through the pin 544. Further, a cylindrical portion is formed around the shaft part 544. Meanwhile, a leading end of the bottom plate 543 is a free end. The bottom plate 543 is pivotable about the pin 544 between a closed position where the bottom plate closes the lower opening of the tablet dispensing measure to hold the tablets in the tablet dispensing measure (the bottom plate 543 shown in a lower part of FIG. 17) and an open position where the bottom plate opens the lower opening to drop the tablets in the tablet dispensing measure 542 to a packing unit (the bottom plate 543 shown in a upper part of FIG. 17). Below the medicine dispensing member is disposed a fixed plate 537, which supports a lower surface of the bottom plate 543 at its upper surface to maintain the bottom plate in the closed position and has stepped portions 537a, 537b at its leading end. A cylindrical portion 547 is formed at a leading end of each of the stepped portions 537a, 537b. FIG. 17 shows neighboring stepped portions 537a, 537b and the bottom plates 543 respectively corresponding thereto.
If the stepped portions 537a, 537b are situated rearward of the shaft part 544 along with movement of the tablet dispensing member, then the bottom plate 543 pivots about the pin 544 from the closed position to the open position. Specifically, as a peripheral surface of the cylindrical portion 545 of the bottom plate 543 moves along a peripheral surface of the cylindrical portion 547 of the fixed plate 537, the bottom plate 543 pivots slowly from the closed position to the open position. When a center of the cylindrical portion 545 of the bottom plate 543 passes by a center of the cylindrical portion 547 of the fixed plate 537, the bottom plate 543 goes into the fully open position.
Positioning the tablet dispensing member for placing one of the bottom plates 543 into the open position is performed only by a drive mechanism of the tablet dispensing member and both the bottom plate 543 and the stepped portions 537a, 537b of the fixed plate 537 do not contribute to such positioning. This leads to poor precision in positioning the tablet dispensing member. As such, it is necessary to ensure a sufficient distance α between the cylindrical portion 545 of the bottom plate 543 and the cylindrical portion 547 of the fixed plate 537 with respect to the bottom plate 43 neighboring one of the bottom plates 543 being in the open position (the bottom plate 543 shown in an upper part of FIG. 17), i.e., with respect to the bottom plate 543 next pivoting from the closed position to the open position (the bottom plate 543 shown in a lower part of FIG. 17). Specifically, in case the precision in positioning the tablet dispensing member is poor and the distance α is narrow, while one of the bottom plates 543 (the bottom plate 543 shown in upper part of FIG. 17) is in the open position, the peripheral surface of the cylindrical portion 545 of the bottom plate 543, which next pivots from the closed position to the open position (the bottom plate 543 shown in a lower part of FIG. 17), reaches the peripheral surface of the cylindrical portion 547 of the fixed plate 537. As a result, a downward displacement (so-called tilting) as indicated by an arrow β in FIG. 17 occurs at a free end of the bottom plate 543b due to a weight of the bottom plate. Thus, the bottom plate 543b is slightly opened and a gap is formed therefrom. Dropping of the tablets in the tablet dispensing measure 542 through the gap may cause failure. Especially, thin tablets are apt to drop unintentionally through the gap.
The distance α corresponds to a pitch between the stepped portions 537a, 537b of the bottom plate 543. As such, to prevent the tablets from dropping unintentionally due to tilting of the bottom plate 543b, the pitch between the stepped portions 537a, 537b must be enlarged. As a result, a movement distance of the tablet dispensing member, which is required to open all the bottom plates 543, is increased and the device becomes larger accordingly.
Further, in a prior art medicine packing device of the above-mentioned type, tablets may adhere on an upper surface of the bottom plate 543 of the tablet dispensing measure or an upper surface of the above-described shutter due to a static electricity, thereby causing a failure.
Patent Document 1: Japanese Laid-Open Patent Application No. 1998-323382